- Natural and man-made changes
- Periodic and non-periodic changes
- Desirable and undesirable changes
- Reversible and irreversible changes
- Physical and chemical changes
- Expansion and contraction of materials
- Expansion and contraction of solids
- Expansion and contraction of liquids
- Expansion and contraction of gases
- Applications of expansion and contraction
INTRODUCTION
• Many changes take place around us on their own.
.jpg)
.jpg)
• In the fields, the crops change from time to time.
.jpg)
• Sometimes, leaves fall from trees, change colour and dry out.
.jpg)
.gif)
.gif)
TYPES OF CHANGES
• Changes occur everywhere, every moment around us.
• Everything in the world is subject to change.
• There are six types of changes:
.jpg)
NATURAL AND MAN-MADE CHANGES
• The changes which are brought about by nature or take place on their own are called natural changes.
• Changes of seasons, rainfall, turning of night into day, earthquakes are all natural changes. These changes cannot be controlled by man.
• Changes which are brought about by man are called man-made changes.
.gif)
.gif)
• These can be controlled by man. Cooking food, burning fuel, cutting paper, etc. are all changes carried out by human beings.
Read More...